Isolating device



Aug. 28, 1962 P. c. TREXLER ISOLATING DEVICE 2 Sheets-Sheet 1 Filed May1, 1957 INVENTOR. P/r/z /P 6? 7kx4 2.

BY M C. 7 W ATTOEA/EX Aug. 28, 1962 P. c. TREXLER ISOLATING DEVICE 2Sheets-$heet 2 Filed May 1, 1957 5 1' E 5 I I 3? q ,1 IIIIIII-VIILUII INVENTOR. F/afi. PH/L/P C. 7fea 5e.

3&5 1,163 Patented Aug. 28, 1962 3,051,163 ISOLATING DEVICE Philip C.Trexler, Niles, Mich, assignor to University of Notre Dame du Lac, NotreDame, Ind., a corporation of Indiana Filed May 1, 1957, Ser. No. 656,39610 Claims. (Cl. 128-1) This invention relates to improvements inisolating devices, and more particularly to a device providing anenclosure for use to confine contamination while experiments and testsinvolving contamination of test specimens are being made, or to excludecontamination from a space within which tests and experiments areconducted. Contamination, as herein mentioned, may be biological orradiological or chemical.

The primary object of the invention is to provide a device of thischaracter which is transparent to permit full visibility thereof and ofcontents thereof, which is inexpensive, and which is light in weight.

A further object is to provide a device of this character which iscollapsible and which can be erected in a place of use quickly andeasily and with a minimum requirement for tools, so that the device canbe used easily in disaster areas and other temporary locations where itis desired to conduct biological tests or other operations, such as thegrowth of cultures for vaccines and like purposes.

A further object is to provide a device of this character having a rigidcollapsible frame to which is supportingly secured an enclosure formedof film material which is of light weight and flexible character.

A further object is to provide a device of this character including anenclosure having walls formed of plastic film, with novel means fordetachably mounting gloves and sleeves in apertures thereinin sealedrelation and without danger of damaging the plastic film or for mountingmovable parts to extend through the film and into the device.

A further object is to provide a device of this character having wallsformed of plastic film which can be readily tested for leaks by theelectrostatic method.

A further object is to provide a device of this character having a metalframe and metal glove-mounting rings which are so protected fromcorrosive atmospheric conditions within the chamber by the film materialforming the chamber as to be completely free from corrosion.

In the drawings:

FIG. 1 is a perspective view illustrating one form of this device;

FIG. 2 is a fragmentary vertical sectional view taken on line 2-2 ofFIG. 1;

FIG. 3 is a fragmentary horizontal sectional view taken on line 3-3 ofFIG. 1;

FIG. 4 is a detail sectional view taken on line 44 of FIG. 1;

FIG. 5 is a vertical sectional view taken on line 5-5 of FIG. 1;

FIG. 6 is a detail sectional view taken on line 66 of FIG. 5;

FIG. 7 is a fragmentary face view illustrating the connection between adrawbolt and a mounting bar, as viewed from the left in FIG. 5;

'FIG. 8 is a schematic view illustrating the manner employed toelectrostatically test the device for the presence of leaks;

FIG. 9 is a sectional view illustrating a modification of the invention;and

FIG. 10 is a sectional view illustrating a modification of the inventionuseful when the enclosure is to confine air under positive pressure.

Referring to the drawings, and particularly to FIGS.

1 to 7 which illustrate an embodiment of the invention particularlysuitable for confining sub-atmospheric pressures, the numeral 10designates the side walls of a sealed chamber or enclosure which alsohas a top wall or walls 12, end walls 14, and a bottom wall 16. Thewalls are continuously marginally and sealingly cemented together todefine an enclosure or chamber within which biological or otherspecimens can be treated, raised, tested or ma nipulated undercontrolled conditions in which pressure is controlled. The walls 10, 12,14 and 16 are preferably formed of flexible sheet material, such as aplastic film.

A frame, preferably of collapsible character and rigid skeletonconstruction, may be provided to mount and support the chamber. Theframe will preferably comprise a pair of end structures which areinterconnected by longitudinal bars, the connection of the partspreferably being detachable, although the frame structure may bepermanently assembled c-r erected and not collapsible. Each of the frameend structures preferably includes upright members 20, bottom member22., converging upper members 24, and intermediate transverse member 26.The members 20, 22, 24- and 26 are preferably formed of metal tubingwhich is of rigid character and may be assembled and connected in anymanner found suitable. As here shown in FIG. 1, the various parts 20,22, 24, 26 are formed separately and are interconnected by fittings 28,each of which joins together the end frame parts cooperating therewithin a substantially common plane. Each of the fittings includes a socketportion projecting substantially perpendicularly to the plane of the endframe and adapted to receive, and preferably detachably secure, an endportion of a longitudinally extending frame member 30, of which five areprovided in the construction of the shape and contour illustrated inFIG. 1. It will be understood that the end frames at the two ends of thedevice are preferably similar and are preassembled so that the compositeor complete frame may be erected therefrom by the simple expedient ofconnecting the longitudinal frame members 30 to the end frames.

The plastic film of which the walls 10, 12, 14 and 16 are formed may beof any type found suitable. Thus the film may be of the vinyl type or ofthe polyester type. The film may be of any thickness found suitable andpreferably will be of a thickness in the range from .002 of an inch to.015 of an inch or possibly more. The film is preferably transparent andflexible and may be chosen of a type to possess desired vapor andmoisture transmission characteristics. The film selected will dependupon the service to which the device is to be put, and in some suchservices air and moisture impervious film may be desired, while in otherservices the film selected may be moisture pervious but impervious toair.

The (film is preferably supported upon the frame in the manner bestillustrated in FIGS. 2 and 3. Thus the side walls 10, the top walls 12,and the bottom wall 16 are preferably formed from a single endless beltor strip of the plastic material which is looped at 32 at properlocations to fit around the longitudinal frame members 30 by means oflongitudinal seals thereof at 34, as illustrated in FIG. 2. Thelongitudinal seals 34 may be formed by cohering contacting folds of thefilm by heat and pressure, or the contacting folds of the film may becemented or otherwise adhered. It is important that the adhesion at 34be continuous so as to provide a seal between the adjacent wall portions10, 12 and 16, as illustrated in FIG. 2, and between the interior ofeach loop and the interior of the chamber. The end walls 14 aremarginally continuously cohered or adhered to the Walls 10, 12 and 16 at36, as illustrated in FIG. 3, as by the use of cement, heat sealingapparatus or any other means found suitable. As shown in FIGS. 1 and 3,the margin w) 36 will preferably extend adjacent to but spaced from theadjacent end frame members 20, 22, 24 and 26. The size of the plasticparts will preferably be such that walls 10,- 12, 14 and 16 will havethe desired degree of tautness when applied over the frame.

In order to work with an manipulate speciments contained within theenclosure, which specimens may be animals, bacteria cultures, plants orany other types of specimens under test, it is necessary for theoperator to be able to reach into the interior of the enclosure withoutdanger of destroying or altering the desired atmospheric conditionwithin the enclosure. Long flexible rubber gloves 40 having their openends marginally sealed at openings in the walls of the enclosure,accomplish this access. The means by which such gloves are mounted witha sealed joint at the flexible film walls of the enclosure may be of thetype illustrated in FIG. 4. Thus a rigid metal ring, such as an aluminumring 42, located at the outer face of the film wall within which theopening 44 is formed, cooperates with a second rigid clamping ring 46located at the inner face of the wall 10. The two rings are securedtogether at spaced points by securing members 48. The inner ring 46preferably has a circumferential groove 50 in the face thereofconfronting the outer ring 42 and located in outwardly spaced relationto the securing members 48 to receive the bead ring 52 upon the free endof the sleeve portion 54 of the glove 40. The sleeve portion 54 ispreferably of a normal circumferential dimension less than the outercircumferential dimension of ring 46 and is stretched or extended aroundthe outer periphery of the inner ring 46 in a position with its headring 52 seated in the groove 50. Thus a portion 56 of the sleeveadjacent the bead ring 52 is clamped in continuous sealing face contactwith the film wall of the enclosure at the outer marginal portions ofthe rings 42 and 46 to effect a continuous seal around the opening 44 inthe film wall 10.

If it is desired to withdraw the glove 40 for inspection, as illustratedat the left in FIG. 1 and in full lines in FIG. 4, the sleeve is passedaround the inner ring 46 and thence through the opening therein andthrough the outer ring 42. Observe that the flexible glove, which ispreferably formed of rubber, serves as a means to protect the metalrings 46 and 42 from exposure to the atmosphere within the enclosure atall times, so that if a corrosive atmosphere is contained therein itcannot attack the metal rings. The same protection against corrosion isprovided by the seals 34 and 36 of the film walls with respect to themetal frame structure. Removal of the gloves for replacement is simpleinasmuch as the securing members 48 can be manipulated easily from theexterior of the device to permit separation of rings 42, 46 for releaseof the glove 40 and application of a new glove thereto, followed byreassembly of the structure.

In the event it is desired to maintain a controlled atmosphericcondition within the enclosure, conduits may be connected in a sealedmanner to supply air and steam or other fluids to the enclosure and todischarge the same from the enclosure. A sealed joint for such a conduitis illustrated in FIG. 9, wherein the closure wall has been designated10 and is gripped around an opening 60 therein by an outer ring 62 andan inner ring 64. The outer ring 62 preferably includes a projectingneck portion 66 which is internally screw-threaded for connection with aconduit 68. Securing members 70 connect the rings 62 and 64 to clamp thewall 10 around the opening 60 and, if desired, a gasket ring 72 may beprovided to facilitate this seal. It will be understood that theconstruction shown in FIG. 9 may be used for other pur- 7 poses, such asa journal for a rotating or reciprocating shaft, by constructing therings 62 and 64 with bore-s to serve as journals.

It is necessary in some uses of the apparatus to provide means foraccess thereto for the purpose of introducing or withdrawing material,or for connection thereof to other enclosures, to permit transfer ofmaterial between connected enclosures. This necessitates the provisionof a releasable closure for an opening in the device which may provideaccess to atmosphere or may lead to an autoclave, a tube leading toanother enclosure, or the like. One manner in which this may beaccomplished is illustr-ated in FJGS. 1 and 5.

Assuming that the access opening is to be formed in the end wall 14, thepart of the frame adjacent to that end wall will include a rigid portion80, such as a ring, secured by members 82 to the adjacent parts of theframe structure, as at the members 20. The ring and the members 82 maybe formed of metal tubing or any other suitable material, and the ring80 will be positioned substantially concentrically with the accessopening in the end wall 14. Drawbolts 84 pass freely through openings inthe ring 80 and also through openings 86 in the film wall 14. A sealedconnection between the shank of each drawbolt 84 and the film wall isprovided, as by means of an elongated flexible plastic sleeve 88 havinga continuous sealed circumferential connection at one end with the filmwall 14 and a continuous sealed circumferential connection with theshank of 'drawbolt 84 at its opposite end. The drawbolt 84 preferablyhas an enlarged head 90 at its inner end and mounts a nut 92, such as athumb nut, at its outer end. Two or more drawbolts are provided andserve as means to position a crossbar or spider member 94, the ends ofwhich are preferably slotted at 96, as illustrated in FIG. 7, forreadily detachable con nection with the d'rawbolt.

The crossbar 94 has a flexible connection with a closure plate 98adapted to seal the access opening. This connection is preferablyeffected by a body of rubber or other flexible material 100 anchored tothe crossbar 94 and the closure plate 98 as by the imbedding therein ofstuds 102 carried by said members 94 and 98 as illustrated in FIG. 6.

The access opening is outlined by an outer ring 104 and an inner ring106 clamping there'between the portion of the enclosure wall at themargin of the opening. The rings may also clamp in sealing faceengagement with the wall of the enclosure around the access opening oneend of a flexible sleeve 108 which may be formed of rubber or plasticmaterial. In the construction shown, the sleeve 108 passes through theopening in the rings 104 and 106, thence around the inner ring 106 andits end margin extends between the rings 104 and 106. An annular pad 110of sponge rubber or other compressible or yieldable material may beprovided at the inner face of the inner ring 106. A tubular member 112is shown in FIGS. 1 and 5 which may constitute either a connecting tubeleading to a similar enclosure unit or an autoclave housing which maymount a removable closure (not shown) at its free outer end as wellunderstood in the art and as generally exemplified in 'Reyniers' PatentNo. 2,244,082, dated June 3, 1941. The connecting member is preferablyin the nature of -a rigid metal tube 112 having a circumferentiallysealed connection with the outer end of sleeve 108. It will beunderstood, however, that the members 108 and 112 are not necessary ineach instance and that they may be omitted if desired. In any event, theaccess opening is sealed by the closure plate 98 which marginallycontinuously sealingly contacts either the inner ring 106, its facing110 or the member '108.

It will be observed that the closure 98 is manipulated from the exteriorof the device by manipulating the nuts 92 either to position thecrossbar 9'4 and the closure plate 98 for sealing engagement of closure98 will the interior structure outlining the margin .of the accessopening, or to release said draw-bolts to permit opening movement of theclosure plate 98 relative to the structure outlining the access opening.The members 88 which seal the drawbolts are preferably slack in thesealed or closed position of the parts so that endwise movement of thedrawbolts 84 in an inward direction may be accomplished withoutdestroying the seal. It will be apparent that when the drawbolts havebeen loosened, an operator may reach through a glove 40 and the crossbar94 may be disengaged from the drawbolts, thus completely freeing thedoor or closure 98 carried thereby for movement relative to theenclosure part adjacent to the access opening to a position permittingfree access through tubular memher 112 to the interior of the structure.It will be understood, of course, that closure 98 may be carried by thecrossbar 94 in any other manner found suitable and not necessarilyrequiring release of the crossbar from the drawbolts to move the closuremember to a position clear of the access opening.

The device lends itself particularly to testing for leaks therein by anelectrostatic method, such as the method now commonly used in testingelectric linemens gloves. One such method is illustrated in FIG. 8,wherein an electrolyte is sprayed to cover the interior and exteriorsurfaces of the film walls of the enclosure. One electrolyte which maybe employed for this purpose constitutes a ten percent calcium chloridesolution containing a detergent as a wetting agent. The electrolytecoatings are designated 120 and 122 in FIG. 8. An insulated electrodewill be passed through an opening in the plastic film prior to theapplication of the electrolyte, said electrode preferably constitutingan insulated or sheathed portion 124 which is cemented and sealed to thefilm wall 10. A bared end 126 of the electrode is then adhered to thefilm at its inner surface in such a manner that it will have electricalcontact with the electrolyte 120 at the inner faceof the film wall. Asecond electrode 128, such as a wire having a bared end portion, isadhered to the film 10 at the outer face thereof in such a manner thatit will have electrical connection with the etxernal electrolyte coating122. A testing circuit as illustrated in FIG. 8 is provided within whicha meter 130 is connected, the same preferably being a milliammeter. Atransformer 132 may provide connection with a source of current, and theelectrode 128 will preferably be grounded.

In conducting the test after the electrolyte has been sprayed on theinterior and exterior surfaces of the enclosure to establish electricconnection with the electrodes 126 and 128, the procedure is as follows:An electrical current is first applied to the circuit at low voltage.The reading of the milliammeter 130 is then observed to ascertainWhether or not any leakage or flow of current occurs in the circuit. Itwill 'be apparent that such leakage may occur if any openings exist inthe film walls of the closure which permit the two coatings 120 and 122to merge and thus close the circuit. If the initial test at low voltageindicates no leakage or fiow of current, the voltage is increasedprogressively until it reaches a desired maximum value, for example,approximately 5,000 volts. If no leakage or current flow is indicated bythe milliammeter under those conditions of applied electrical potential,the operator is assured that the film enclosure is completely sealed andthat the device is safe for use to maintain a sterile atmosphere, tocontain and confine a contaminated atmosphere, or to maintain a desiredpressure condition.

It will be evident from the foregoing that the device is characterizedby low cost as compared to the cost of apparatus formed of metal orother materials. It is further characterized by the inherenttransparency of the film material which permits vision of the contentsof the enclosure at any time and eliminates the need for provision ofsight openings in the device. The collapsibility of the device rendersit readily portable and enables its use at locations of disasters orother emergency conditions. Also, the collapsibility .of the filmenclosure permits enclosures formed of some films to be folded forinsertion into an autoclave for sterilization thereof. The devicepossesses a wide range of flexibility with respect to the uses to whichit may be put and the conditions under which it is used, assuming, ofcourse, that materials are selected which will meet those conditions.Thus in some instances where a sterile condition is desired to bemaintained within the enclosure, the film must be selected of a materialwhich is impervious to both air and moisture. In some instances, wherecontamination is to be confined, it may be immaterial whether thestructure is moisture pervious but important that it be impervious toair.

In order to minimize the strain on the structure at the points at whichconnections for gloves or closures or the like are provided, it isdesirable to make the rings which clamp the film around the openings ofa light weight metal, such as aluminum. These rings must in eachinstance, however, be sufficiently rigid to continuously marginallyclamp and seal the film when drawn together. Furthermore, the structureat all joints and connections must be arranged to distribute uniformlyand radially the stresses of the connection and the rings and otherparts or, in the case of the closure 98, must be constructed to transmitstresses to the supporting frame to protect the plastic film of whichthe wall is formed.

In cases where the enclosure is to contain air under positive pressureand hence be inflated, so that collapse of the flexible walls is not aproblem, the frame may be omitted, or a simpler connection between theenclosure and a frame or support than above described may be provided.In such cases it may be desirable to insert a rigid panel in theenclosure as shown in FIG. 10, to assist in controlling the shape of theinflated enclosure and to hold it in desired location.

While the preferred embodiments of the invention have been illustratedand described, it will be understood that changes in the constructionmay be made within the scope of the appended claims without departingfrom the spirit of the invention.

I claim:

1. An isolating device comprising an enclosure formed of flexible filmmaterial, said enclosure having an opening, a flexible access glovehaving a sleeve portion, inner and outer rigid registering rings,securing means drawing together said rings for clamping said filmmaterial therebetween continuously around said opening, said glovesleeve extending around the inner ring with its open end portioninturned and clamped between said rings, said glove having elasticity toaccommodate flat positioning of said inturned end portion in continuoussealed wrinkle-free engagement with said film material and with theclamping surface of said outer ring around said opening outwardly ofsaid securing means.

2. An isolating device as defined in claim 1, wherein the open end ofthe internal portion of said sleeve is defined by a bead ring, and theclamping face of said inner ring has an endless bead-receiving groovetherein.

3. An isolating device comprising an enclosure formed of flexible filmmaterial, said enclosure having an opening, a pair of registering ringshaving complementary cooperating film-clamping surfaces confrontingopposite faces of said film material continuously around said openingand securing means connecting inner portions of said rings to draw theminto film-clamping relation.

4. An isolating device comprising a frame, an enclosure supported bysaid frame and formed of flexible film material, said enclosure havingan opening, a rigid ring unit clamping said film concentrically with andcontinuously and uniformly surrounding said opening and consisting ofconcentric rings at opposite sides of said film and draw boltsconnecting said rings at their inner margins to draw said rings intoclamping relation to said film.

5. An isolating device as defined in claim 4, and a removable closurespanning said opening, and means releasably supporting said closure incontinuous sealing relation to said ring unit.

6. An isolating device comprising a support, an enclosure connected tosaid support and formed of flexible film material, said enclosure havingan opening, a rigid ring unit carried by said film concentrically withand surrounding said opening, a closure spanning said opening, and

. means carried by said support and releasably supporting said closurein continuous sealing relation to said ring unit, said ring unitincluding an annular yielding member engaged continuously by themarginal portion of said closure.

8. An isolating device comprising a support, an enclosure connected tosaid support and formed of flexible film material, said enclosure havingan opening, a rigid ring unit carried by said film concentrically withand surrounding said opening, a closure spanning said opening, meanscarried by said support and releasably supporting said closure incontinuous sealing relation to said ring unit, said closure beinglocated within said enclosure and said closure supporting meansincluding a drawbolt extending through an opening in said enclosure, anda flexible elongated tubular member encircling and sealed to said boltat one end and sealed around said last named opening at its oppositeend.

9. An isolating device as defined in claim 1, wherein said enclosure issubstantially air tight and electrolytic coatings cover the inner andouter surfaces of said enclosure, means for adhering conductors to theinner and outer surfaces of said enclosure in contact with saidcoatings,

means connecting said conductors in an electric circuit.

normally broken by said coated film material positioned in theatmosphere, means for electrically charging said circuit, and means formeasuring flow of electrical current in said circuit.

10. An isolating device as defined in claim 1, wherein said enclosure issubstantially air tight and electrolytic coatings cover the inner andouter surfaces of said enclosure, conductors adhering to the inner andouter surfaces of said enclosure in contact with said coatings, meansfor imposing an electric potential on said conductors while saidenclosure is positioned in the atmosphere, and means for measuring flowof electrical current between said coatings and conductors.

References (Iited in the file of this patent UNITED STATES PATENTS2,243,999 Chapple June 3, 1941 2,496,175 Perry Jan. 31., 1950 2,497,832Fairlamb Feb. 14, 1950 2,503,992 Becker Apr. 11, 1950 2,624,333 Dixon etal. Jan. 6, 1953 2,646,057 Blanchard July 21, 1953 2,652,047 Luck et alSept. 15, 1953 2,659,364 Bruckman Nov. 17, 1953 2,664,890 Wallace Jan.5, 1954 2,695,608 Gibbon Nov. 30, 1954 2,702,546 Gilroy et al Feb. 22,1955 2,778,362 Pollock et a1 Jan. 22, 1957 2,786,740 Taylor et a1 Mar.26, 1957 2,810,390 Wallace Oct. 22, 1957 2,811,164 Ames Oct. 29, 19572,822,803 Huxley Feb. 11, 1958

